Quick diagnosis tells us Erie walleye not in peril

OUTDOORS

May 22, 2011

Lake Erie walleye fisherman are some of the quickest around when it comes to reaching for the panic button. Weather, water temperature, clarity issues, sustained winds, long slow periods, commercial operations, rare viruses - any and all of those make the list of impending doom when these anglers sense something might be wrong in that big bathtub of a great lake.

There is no logical explanation for why some of these guys seem to look around, searching for a reason bad karma would be headed their way. Maybe they are ultra superstitious, a tad paranoid, or prone to sustained bouts of overreacting.

Or most likely, these fishermen are old enough to have lived through the bleak times, when walleye fishing on the lake was poor, or almost non-existent. They were around when the lake nearly was given up for dead, and they live in constant fear that this precious resource will be threatened again, or possibly lost.

That is why a recent fish kill on the lake that affected the prized walleye created an immediate sense of dread among the fishermen. They saw clusters of floating fish and assumed the worst.

It turns out that after examining some of the dead fish, the location of the kill, and the extent of the phenomena, fisheries biologists concluded it was simply a quirk of nature, or natural causes, that resulted in the recent deaths of several thousand walleye.

The experts say the fish got hit with a rare double-whammy when the stress of the spawning period put them in a weakened state, and an usually long, cold, and stormy spring pushed some of them over the edge physically.

Many of the dead fish were concentrated in the areas around the reef complexes, providing another piece of evidence that spawning fish were the victims of the kill since those reefs are the primary spawning areas out on the lake. There was no evidence the fish were afflicted with any virus.

Aerial surveys put the estimated number of dead fish in the thousands, which might seem like a lot initially, until you factor in the numbers. With a total walleye population in the lake estimated at more than 20 million, the freak fish kill hit just a tiny fraction of the massive herd of fish.

But seeing those dead fish floating on the surface of the lake freaked out more than a few fishermen. They have followed the walleye's tumultuous history on the big lake.

There was a booming commercial fishery for walleye on Lake Erie in the 1950s, but soon overharvest, pollution and habitat damage sent the walleye population into a nosedive. By 1970, mercury contamination made walleye from Erie unsafe to eat, noxious algae blooms suffocated large areas of the lake and many who had survived on the lake's bounty sadly declared it dead.

Significant measures to control pollution and clean up the lake started to show benefits by the late 1970s. The water slowly cleared as it was cleaned up. The walleye population rebounded, and the fish that anglers were catching were much healthier.

By the late 1980s, the walleye population had boomed to around 70 million and times were good. Several times since then, the combination of poor hatches and additional threats posed by invasive species and other environmental factors have caused the walleye population to dip enough to put a scare into the Lake Erie fishermen.

Fisheries biologists from Ohio, Michigan and Canada have combined forces to better manage the walleye in the lake, and adjust size and bag limits as the population fluctuates. Their efforts are critical, since tourism in just the seven Ohio counties that border the lake brings in more than $7.4 billion a year, and fishing is the primary component of that tourism.

It is great news that the fish kill was very minor and the result of an unusual set of circumstances, not a much larger, sustained threat. We can't fault the Erie fisherman for sounding the alarm. In doing so, they likely got us to the answer in this mystery a lot faster.